A bilirubin blood test measures the level of bilirubin in your bloodstream. Bilirubin is a yellow-orange substance produced during the normal breakdown of red blood cells. The liver processes bilirubin before it is removed from the body through bile.

Healthcare providers commonly use a bilirubin blood test to help evaluate liver function and investigate conditions affecting the liver, gallbladder, bile ducts, or the breakdown of red blood cells. The test is often performed as part of routine blood work or alongside other liver function tests to provide a more comprehensive assessment.

  • Key Takeaways
  • A bilirubin blood test measures the amount of bilirubin in the blood.
  • The test helps evaluate liver function and biliary health.
  • It may be recommended to investigate jaundice or abnormal liver function.
  • The procedure involves a simple blood sample and usually takes only a few minutes.
  • Test results should always be interpreted together with symptoms, medical history, and other laboratory findings.

What is a Bilirubin Blood Test?

A bilirubin blood test measures the concentration of bilirubin circulating in the bloodstream. Bilirubin is produced when the body naturally breaks down aging red blood cells. After it is formed, bilirubin travels to the liver, where it is processed and released into bile before eventually leaving the body through the digestive system.

When bilirubin is not processed or eliminated normally, its level in the blood may increase. Measuring bilirubin can provide valuable information about liver function and conditions affecting bile flow or red blood cell breakdown.

Why is a Bilirubin Blood Test Performed?

A bilirubin blood test is performed to measure the level of bilirubin in the bloodstream and assess how the body processes this substance. Healthcare providers commonly use the test to evaluate liver function and investigate conditions affecting the liver, gallbladder, bile ducts, or the breakdown of red blood cells.

To Evaluate Liver Function

Bilirubin testing helps healthcare providers assess how effectively the liver is processing and removing bilirubin from the body. It is often included as part of a broader evaluation of liver function.

To Help Diagnose Jaundice

A bilirubin blood test is commonly performed when a person develops yellowing of the skin or the whites of the eyes. Measuring bilirubin levels may help determine whether jaundice is related to liver function or bile flow.

To Assess Bile Duct Disorders

Conditions affecting the bile ducts may interfere with the normal elimination of bilirubin. The test can provide valuable information when bile duct obstruction or other biliary conditions are suspected.

To Investigate Increased Red Blood Cell Breakdown

When red blood cells break down more rapidly than normal, bilirubin production increases. A bilirubin blood test may help healthcare providers investigate whether increased red blood cell breakdown is contributing to elevated bilirubin levels.

Who May Need a Bilirubin Blood Test?

A healthcare provider may recommend a bilirubin blood test for individuals with symptoms that suggest a liver or biliary disorder. The test may also be ordered as part of routine blood work or to monitor existing liver conditions and evaluate abnormal liver function test results.

You may need a bilirubin blood test if you experience:

  • Yellowing of the skin or eyes 
  • Dark-colored urine
  • Pale or clay-colored stools
  • Abdominal discomfort
  • Nausea
  • Fatigue
  • Abnormal liver function test results

How Should You Prepare for a Bilirubin Blood Test?

Preparation for a bilirubin blood test depends on whether it is performed alone or alongside other laboratory tests. Your healthcare provider will explain whether fasting or temporary adjustments to medications are necessary before the blood sample is collected.

Before the test, you may be advised to:

  • Fast for several hours if required
  • Inform your healthcare provider about prescription medications, over-the-counter medicines, and dietary supplements
  • Follow any additional instructions provided before the blood draw

Following your healthcare provider's recommendations helps ensure the most accurate test results.

What Happens During the Procedure?

A bilirubin blood test is a simple laboratory procedure that involves collecting a small blood sample from a vein in your arm. The sample is then sent to a laboratory, where bilirubin levels are measured and included in your test results.

During the procedure:

  • A healthcare professional cleans the skin over a vein.
  • A needle is inserted into the vein to collect a blood sample.
  • The blood is collected into a test tube.
  • The needle is removed, and pressure is applied to the puncture site.

The procedure usually takes only a few minutes, and most people can return to their normal activities shortly afterward.

Are There Any Risks?

A bilirubin blood test is considered a safe and routine procedure with very few risks. Most people experience only mild, temporary discomfort, and serious complications are rare.

Possible minor side effects include:

  • Mild discomfort during needle insertion
  • Temporary bruising
  • Slight bleeding at the puncture site
  • Occasional lightheadedness

If you experience persistent pain, swelling, or excessive bleeding after the blood draw, you should contact your healthcare provider.

Understanding Bilirubin Blood Test Results

Bilirubin blood test results should always be interpreted by a healthcare professional in the context of your symptoms, medical history, physical examination, and other laboratory findings.

What Are Normal Bilirubin Levels?

Normal bilirubin levels may vary slightly depending on the laboratory performing the analysis and the testing methods used.

Your healthcare provider will interpret your results using the laboratory's reference range and determine whether additional evaluation is necessary.

What Can High Bilirubin Levels Mean?

Elevated bilirubin levels may indicate that bilirubin is not being processed or eliminated normally.

Possible causes include:

  • Liver disease
  • Bile duct obstruction
  • Gallstones
  • Increased breakdown of red blood cells

An elevated bilirubin level alone does not establish a diagnosis. Additional laboratory tests, imaging studies, and clinical evaluation may be needed to identify the underlying cause.

Clinical Insight: Bilirubin Is One Part of Liver Assessment

A bilirubin blood test provides important information about liver and biliary function, but it is rarely interpreted on its own. Healthcare providers typically evaluate bilirubin alongside other liver function tests, imaging studies, medical history, and physical examination findings to obtain a more complete picture of liver health.

Which department should I visit?

Individuals with abnormal bilirubin levels, jaundice, or symptoms suggestive of liver or biliary disorders may consult the following departments:

Categories

Biochemistry Laboratory Bone Marrow Transplantation Cardiology Cardiovascular Surgery Check-up Child Psychology Dermatology Ear Nose and Throat ( ENT ) Endocrinology and Metabolic Diseases Gastroenterology General Surgery Gynecological Oncology Gynecology and Obstetrics Hematology Home Health (Care) Services In Vitro Fertilization (IVF) Infectious Diseases Internal Diseases Medical Biochemistry Medical Genetics Medical Oncology Nephrology Neurology Neurosurgery Nuclear Medicine Nutrition and Diet Ophthalmology Oral and Dental Health Organ Transplant Orthopedics and Traumatology Pediatric Allergy and Immunology Pediatric Cardiology Pediatric Cardiovascular Surgery Pediatric Hematology & Oncology Pediatric Neurology Pediatric Surgery Pediatrics Perinatology "High Risk Pregnancies" Physical Therapy and Rehabilitation Plastic Surgery Psychiatry Psychology Pulmonology Radiation Oncology Radiology Rheumatology Speech and Language Therapy Thoracic Surgery Urology View All

Frequently Asked Questions About Bilirubin Blood Tests

A bilirubin blood test measures the amount of bilirubin in the bloodstream to help evaluate liver function and investigate conditions affecting bilirubin metabolism.

Healthcare providers commonly order this test to evaluate liver function, investigate jaundice, assess bile duct disorders, or help determine the cause of elevated bilirubin levels.

Depending on the reason for testing, your healthcare provider may ask you to fast before the blood sample is collected. Always follow the preparation instructions provided before your appointment.

Most people experience only brief discomfort during the blood draw. The procedure is quick and considered minimally invasive.

High bilirubin levels may be associated with liver disease, bile duct obstruction, gallstones, or increased red blood cell breakdown. Further evaluation is usually required to determine the exact cause.

The blood collection procedure typically takes only a few minutes, while laboratory processing times may vary.

A bilirubin blood test is one part of a comprehensive liver evaluation and is interpreted together with other laboratory tests, imaging studies, and clinical findings.

Depending on the underlying cause, patients may be evaluated by specialists in Gastroenterology, Internal Medicine, or Hepatology.

Medicana Web and Editorial Board

Created at

08.07.2026 08:33

Updated at

08.07.2026 09:19

Creator

Medicana Web and Editorial Board